Assessing heterogeneity in meta-analysis: Q statistic or I2 index?
Psychological Methods (2006) - Comment
pubmed: 16784338  doi: 10.1037/1082-989x.11.2.193  issn: 1082-989x  issn: 1939-1463 

Tania B. Huedo-Medina, Julio Sánchez-Meca, Fulgencio Marín-Martínez, Juan Botella